Granular Controlled Release Agrochemical Compositions and Process for the Preparation Thereof

ABSTRACT

A granular agrochemical composition is disclosed including a granular core material having a water soluble portion with a first coating layer applied on the surface of the core material and a second coating layer applied on the surface of the first coating layer. The first coating layer includes a wax composition having a biologically active ingredient incorporated therein and the second coating layer includes a polymeric composition. The granular agrochemical composition exhibits a controlled rate of release of the biologically active ingredient therefrom over a period greater than about  30  days from the date of initial exposure of the granular composition to moisture whereby essentially all of the biologically active ingredient incorporated in the wax material of the first coating layer is released from the granular composition before the water soluble portion of the granular core material is released from the granular composition.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to granular agrochemical compositions andto processes for producing such compositions. More particularly, itrelates to controlled release agrochemical compositions having a firstcoating layer comprising a wax composition with a biologically activeingredient incorporated therein applied on the surface of a corematerial and having a second coating layer comprising a polymericcomposition applied on the surface of the first coating layer and toprocesses for preparing such compositions.

2. Description of Related Art

Agrochemicals as referred to herein include biologically activeingredients/plant protection products such as insecticides, herbicides,fertilizers, growth regulators, pheromones, biostimulants, acaricides,miticides, nematocides, fungicides and the like. Such agrochemicals arewell known and are in common usage for controlling pests and diseasesand for promoting plant growth in agriculture. In practice, it isimportant to make a sufficient amount of such agrochemical or activeingredient available to the biological system in order to control pestsor disease or to promote growth. Too much active ingredient, however, isinefficient and not desired because of environmental and economicconcerns. Furthermore, higher amounts of active ingredient lead toincreased risks of leaching to ground water or surface water. Higheramounts can also lead to phytotoxicity for the crop. Insufficient levelsof active ingredients results in lack of control of the pest andincrease the risk of resistance.

Thus, it is generally known that it is important to deliver the correctamount of active ingredient to the crop for control of the pest ordisease and to promote growth over a given period of time. However,multiple applications of active ingredients becomes labor and costintensive. With conventional applications of liquid or powderformulations, relatively high amounts of active ingredients are appliedseveral times to assure control of pests over a longer period of time,typically 3-6 times for seasonal control, and users are exposed to theactive ingredients during each application, which is undesirable.

When active ingredients are applied in granular form instead of byspraying or dusting, the risk of exposure to the active ingredient ismore limited. After application of a granular pesticide the activeingredient is released to the soil under the influence of water. Therelease rate varies depending on the formulation of the granule. Thegranules can be divided into two categories. The first category releasesthe active ingredient quickly and has to be applied several times duringthe season. The second category releases the active ingredient over aperiod of time and provides control of pests during an extended periodup to a whole season. To control pests over a longer period of time theconcentration of active ingredient must be above the minimal effectivelevel during the whole period. To maintain this effective concentration,the loss of active ingredient via leaching, degradation and uptake bythe plant must be compensated. The rate of degradation and leachingdepends on the active ingredient and the amount that is lost, isdirectly related to the concentration of the active ingredient in thesoil. Thus high concentrations result in relatively more degradation andleaching.

In general, known controlled release granular active ingredients sufferserious limitations. They generally do not deliver the active ingredientto the biological system for periods of greater than about 30 days fromthe date of initial exposure to moisture and/or they do not completelyrelease the active ingredient. The practical limitations of systems thatrelease the active ingredient in less than about 30 days are that theymust be periodically reapplied during the growing season resulting inadditional cost. The limitations of systems which do not completelyrelease the active ingredient in the desired period of time are relatedto efficiency. More active ingredient must be used to compensate for theportion which does not release effectively. This incurs additional costto the user. Furthermore, the residual, unreleased active ingredientposes an environmental threat and can lead to biological resistance inthe pest. Active ingredient that is not released cannot be used forcontrolling a pest or disease and will give undesirable residues ofactive ingredient. In the long run this can lead to build up ofchemicals in soil and this is even less desirable. Without residuesafter the release period soil can be recycled without any risk forsucceeding crop. The use of lower amounts of active ingredients and highefficiency are especially desired from an economical and environmentalpoint of view.

A number of approaches have been taken heretofore in production ofcontrolled release granular agrochemical compositions. For example, EPPatent 079668 discloses an encapsulated pesticide product wherein agranular core is coated with a pesticide and then a plurality of layersof a membrane like coating are applied over the pesticidal coat toenable controlled release of such pesticide over a period of time uponcontact with water. However, the products disclosed in EP Patent 079668are structurally distinct from the products of the present inventionand, accordingly, disadvantageously fail to exhibit a controlled rate ofrelease of the pesticide over a period greater than about 30 days fromthe date of initial exposure of the product to moisture in a manner suchthat essentially all of the pesticide coated on the core is releasedfrom the granular composition before the water soluble portion of thecore material is released from the product as is achieved with thecompositions of the present invention.

U.S. Pat. No. 6,682,751 discloses a granular pesticide comprising a corematerial coated with an inner polymer membrane formed in-situ on thecore material with a pesticide applied to the inner polymer membrane andan outer controlled release polymer membrane formed in situ on thepesticide to permit controlled release. The pesticide may beincorporated in several “sandwich” layers. Again, the products of U.S.Pat. No. 6,682,751, are structurally different from the products of thepresent invention and fail to exhibit a controlled rate of release ofthe pesticide over a period greater than about 30 days from the date ofinitial exposure of the product to moisture in a manner such thatessentially all of the pesticide coated on the core is released from thegranular composition before the water soluble portion of the corematerial is released from the product.

U.S. Pat. No. 6,080,221 discloses the coating of porous surfaces offertilizer particles with tenacious pesticide-resin solids to formattrition resistant fertilizer-pesticide combination particles. In thisdisclosure, the pesticide is dispersed in a resinoid matrix, which issubsequently bonded onto and into the fertilizer surface. Patent U.S.Pat. No. 4,971,796 describes another slow release granular product inwhich the pesticide is matrixed into the coating. The granule comprisesone layer of proteinacious material or more layers of proteinaciousmaterial with intermediate spacing layers. The active ingredient is inthe proteinacious layer and is released when this layer degrades. Therelease rate is changed by varying the cross linking or the thickness ofthe layer. The products of U.S. Pat. No. 6,080,221 and U.S. Pat. No.4,971,796 fail to exhibit a controlled rate of release of the pesticideover a period greater than about 30 days from the date of initialexposure of the product to moisture in a manner such that essentiallyall of the pesticide coated on the core is released from the granularcomposition before the core material is released from the product.

U.S. Pat. No. 6,187,074 and U.S. Pat No. 6,309,439 disclose a fertilizercoated with a carboxyl-carrying ethylene copolymer, thecarboxyl-carrying ethylene copolymer being composed of 75%-90% by weightethylene and from 10%-25% by weight of an alpha-olefinically unsaturatedC3-C8 carboxylic acid. The coated fertilizer particles specifically donot contain any crop protection chemicals. Thus, the products disclosedin these patents fail to exhibit a controlled rate of release of thepesticide over a period greater than about 30 days from the date ofinitial exposure of the product to moisture in a manner such thatessentially all of the pesticide coated on the core is released from thegranular composition before the core material is released from theproduct.

U.S. Pat. No. 6,693,063 discloses products that are structurallydistinct from the present compositions teaching wax microcapsules andwax dispersion of pesticides in the absence of a water soluble corematerial. Other encapsulated pesticides which do not include watersoluble core materials are disclosed in Japanese Examined PatentPublication JP-B 5002/1989, JP-A 9304/1994 and JP-A 72805/1994.

Other pesticides displaying matrix release systems are disclosed in.U.S. Pat. No. 4,435,383 wherein solid controlled release pesticidalproducts are formed comprising an active ingredient incorporated in ahomogeneous combination with a polymer by melting the polymer and mixingit with the active ingredient. During this process additionalcross-linking agent are added. Another matrix based pesticide isdisclosed in U.S. Pat. No. 5,516,520 wherein a pesticidally activeingredient is encapsulated in a starch-borax-urea matrix. The slowrelease from this matrix is limited to oil-soluble pesticides. Therelease rate is changed by varying the amount of urea.

EP Patent 0755370 discloses other matrix release products which aremixtures of a nitromethylene or related substances with fertilizers andglue. EP Patent 1063215 describes briquettes that slowly release activeingredients. The slow release is obtained via absorption or adsorptionof the active ingredient onto solids with high surface area.

The matrix systems all demonstrate release mechanisms wherein therelease of active ingredients from the matrix systems is via desorptionfrom an absorped state or by diffusion and not by an osmotic (pump)release mechanism as employed herein. The release rate of such matrixsystems depends on the concentration of the active ingredient in thesystem. Thus, the release rate of such granules decreases over timeresulting in initial fast release of active ingredients which provideshigh amounts of active ingredient in the soil at the start, and a slowrelease at the end.

Other types of agrochemical products that can release an activeingredient over a period of time are biodegradable systems such as thosedisclosed in U.S. Pat. No. 4,062,855 wherein active ingredients areincorporated into a polymer that are released via biodegradation. U.S.Pat. No. 4,267,280 describes a product that has a biodegradable polymersystem that contains the pesticide. It releases the pesticide dependingon environmental conditions via hydrolyses or depolymerization.

A disadvantage of these biodegradable products is that the release ofactive ingredient depends on the speed of degradation of the polymer andthis degradation depends on the activity of ambient microorganisms. Theactivity of the microorganisms can vary greatly depending on the soiltype and local environmental conditions, types of microbes, pH,temperature, moisture and the like. Thus, the release rate of activeingredients varies and it is difficult to match the release preciselywith the minimal required active ingredient concentrations.

Other coated granular pesticidal compositions are disclosed inInternational Patent Publication WO 02/05641 wherein a pesticidalcomposition is disclosed that can slowly release an active ingredient.That publication discloses the preparation of several granular materialswith different numbers of coating layers or properties of the coatinglayers. Each of the granular materials has its own release profile. Byblending the different granules they can obtain the desired releasepattern of the product. The variation of release is purely based oncoating properties and not on solubility of components in theformulation.

EP Patent 0966882 discloses a controlled release granular productwherein only single granules exhibit a delay of release after which thepesticide is released. Thus, after a period of time, a particulargranule breaks open and delivers a portion of active ingredient to theenvironment. The release over a period of time is established bycombining multiple ‘delayed-release’ granules, which all have differentdelay times. The granules themselves do not exhibit controlled releaseproperties, only a delayed release.

EP Patent 1148107 discloses a coating procedure for granules with a lowcontent of volatile substances. This coating procedure ensures that therelease function of the granules does not change in two weeks time.

Another example of formulations of this general type is disclosed inInternational Patent Publication WO 99/07654 comprising encapsulatedfertilizers with a polymeric envelope that contains a hormone (e.g. anauxin or cytokinine). The hormone is mixed with a monomer that form apolymeric envelope. Again, the products disclosed in this reference donot exhibit a controlled rate of release of the pesticide over a periodgreater than about 30 days from the date of initial exposure of theproduct to moisture in a manner such that essentially all of thepesticide coated on the core is released from the granular compositionbefore the core material is released from the product.

In view of the benefits that can be derived from agrochemicalcompositions that provide controlled release of active ingredientsincluding efficiency and economy of use of the active ingredients, thereduced environmental impact achieved, the ability to employ a singleapplication of the composition for extended control of pests anddiseases, reduction in user exposure to the compositions, it is clearthat new, more technically advanced agrochemical products would behighly desirable. In particular, a desired objective is to provideagrochemical compositions that provide extended useful life withessentially complete release of an active ingredient occurring over aperiods of greater than about 30 days from the date of initial exposureto moisture.

Thus, prior art agrochemical compositions have fallen short in providingdesired functionality and the present invention is intended to overcomesuch problem by providing compositions which functionally demonstrate acontrolled rate of release of the active ingredient over a period oftime greater than about 30 days from the date of initial exposure of thecompositions to moisture in a manner such that essentially all of theactive ingredient coated on the core is released from the granularcomposition before the core material is released from the product.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to granular agrochemical compositionswhich exhibit functionality wherein essentially complete release of theactive ingredients occurs over a period of time greater than about 30days. These granular compositions comprise a granular core materialwhich, preferably, is at least partially water soluble, coated with afirst coating layer comprising a wax material having a biologicallyactive plant protection product or active ingredient incorporatedtherein and having a second coating layer comprising a polymericcomposition applied on the surface of the first coating layer.

The present invention involves the development of a new system forrelease of active ingredients, such as herbicides, growth regulators,pheromones, bactericides, insecticides, acaricides and fungicides andthe like, over a defined period of time with high efficiency.

In a preferred embodiment, the granular agrochemical composition of thepresent invention exhibit a controlled rate of release of thebiologically active ingredient therefrom over a period greater thanabout 30 days from the date of initial exposure of the granularcomposition to moisture whereby essentially all of the biologicallyactive ingredient incorporated in the wax material of the first coatinglayer is released from the granular composition while at least aresidual amount of the core material remains in the granularcomposition. In this regard, it has been found that the release rate ofthe compositions can be influenced by changing the coating properties,the solubility of the core-material and by adjusting various others ofthe product constituents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 illustrates the release rate of a granular agrochemicalcomposition of the present invention.

FIG. 2 illustrates the release rate of another embodiment of thegranular agrochemical compositions of the present invention.

FIG. 3 illustrates the release rate of a another embodiment of thegranular agrochemical compositions of the present invention.

FIG. 4 illustrates the release rate of another embodiment of thegranular agrochemical compositions of the present invention.

FIG. 5 illustrates the release rate of another embodiment of thegranular agrochemical compositions of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The products of the present invention comprise granular agrochemicalcompositions including a granular core material having a first coatinglayer applied on the surface of the core material and a second coatinglayer applied over the surface of the first coating layer. The firstcoating layer comprises a wax material having a plant protection productincorporated therein and the second coating layer comprising a polymericcomposition.

The granular composition of this invention exhibit a controlled rate ofrelease of a plant protection product therefrom over a period greaterthan about 30 days from the date of initial exposure of the granularcomposition to moisture, preferably up to about 104 weeks after initialexposure to moisture, whereby essentially all of the plant protectionproduct incorporated in the wax material of the first layer is releasedfrom the granular composition while at least a residual amount of thewater soluble core material remains in the granular composition andmethods to make such a granular agrochemical composition.

Thus, the present compositions enable lower application rates for thesame period of control because the plant protection products isessentially completely released at a control rate over a period ofgreater than 30 days, preferably up to about 104 weeks, from the date ofinitial exposure to water. The products of this invention have a highefficiency. This means that essentially all of the active ingredient,preferably greater than 90% of the initial weight of the activeingredient in the wax coating layer is released to the environmentbefore the water soluble content of the core material is completelydepleted.

The process for preparing the granular compositions of the presentinvention which exhibit essentially complete release of the activeingredient over a period greater than about 30 days, preferablycomprises coating a core material with a first coating layer comprisinga wax material having a biologically active ingredient incorporatedtherein and applying a second coating layer comprising a polymericcomposition applied over the surface of the first coating layer.

Most preferably, the core material is at least partially water solubleensuring transport of water to the granule through the first and secondcoating layers via osmosis. The “osmotic” transport of the ingredientsoccurs as a result of the pumping of water into and a solution out ofthe granule and continues until all core material has been released.Accordingly, once dissolved, the water dissolvable core material as wellas the biologically active ingredient in the first coating layer aretransported out of the granule.

Exemplary of suitable core materials for use herein are fertilizers suchas ammonium sulfate, potassium nitrate, potassium sulfate, urea,ammonium nitrate, monopotassium sulfate, ammonium phosphate,super-phosphate, calcium phosphates, potassium phosphate, potassiumchloride, magnesium oxide, magnesium sulfate, dolomite and the like orany fertilizers obtained from compounding a mixture of thesefertilizers. Also, non-active materials such as sugar and other granularmaterials may be employed as the core material herein, if desired.

In a preferred embodiment of this invention, the core materials compriseat least one secondary nutrient and/or micronutrient. Suitable secondarynutrients include calcium, magnesium, sulfur and mixtures thereof.Suitable micronutrients, in chelated or non-chelated form, include ironcopper, zinc, manganese, boron, cobalt, chlorine, sodium, molybdenum andmixtures thereof.

With regard to the wax composition to be employed to form the firstcoating layer, in a most preferred embodiment of this invention, the waxshould be water soluble to facilitate an even better dissolution of theactive ingredient in the coating layer.

The granular agrochemical composition of the present invention exhibitsa controlled rate of release of a plant protection product (activeingredient) therefrom over a period greater than about 30 days from thedate of initial exposure of the granular composition to moisture wherebyessentially all of the plant protection product incorporated in the waxmaterial of the first layer is released from the granular compositionwhile at least a residual amount of the water soluble core materialremains in the granular composition.

Exemplary, of suitable biologically active ingredients for use hereinare pesticides, insecticides, herbicides, fungicides, fertilizers,growth regulators, pheromones, biostimulants, acaricides, miticides,nematocides and mixtures thereof.

For example, one or more suitable herbicides for use herein includedichlorophenoxyacetic acid, dichloropicolinic acid, dichloro-o-anisicacid, diquation, phosphonomethyl)glycine,isopropyl-4-methyl-5-oxo-2-imidazolin-2-YL)-nicotinic acid, methyl2-(((((4-methoxy-6-methyl-1,3,5-triazin-2-YL)amino)carbonyl)amino)sulfonyl)benzoate,butyl-4-(2,4-dichloro-5-isopropoxyphenyl-delta2-1,3,4-oxadiazoline-5-one(Note: delta2=delta superscript 2),ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine, ehtyl2-chloro-5-4-chloro-(5-difluoromethoxy)-1-methyl-1H-pyrazol-3-YLY-4-fluorophenoxyacetate(CAS name), dichloro-8-quinolinecarboxylic acid,trichloro-2-pyridinyloxyacetic acid, glyphosate, glufosinate-ammonium,derivatives of phenoxyacetic acid, phenoxypropionic acid, phenoxybutyricacid, 4-amino-3,5,6-trichloro-picolinic acid, phenoxyethyl sulphuricacid, halogeneated benzoic acid, halogenated acetic acid, halogenatedpropionic acid, phenylurea, or bipyridylium, and certain mineral saltsof sodium chlorate, sodium or potassium 2,4-dichlorophenoxyacetate,sodium or potassium 4-chloro-2-methylphenoxyacetate, sodium or potassium2,4,5-trichlorophenoxyacetate, sodium or potassium2-(4-chloro-2-methylphenoxy)-propionate, sodium or potassium2-(2,4-dichlorophenoxy)-propionate, sodium or potassium4-(2,4-dichlorophenoxy)-butyrate, sodium or potassium4-(4-chloro-2-methylphenoxy)-butyrate, sodium or potassium4-(2,4,5-trichlorophenoxy)-butyrate, sodium or potassium4-amino-3,5,6-trichloropicolinate, sodium2-(2,4-dichlorophenoxy)-ethylsulfate, 2,3,6-trichlorobenzoic acid,3,6-dichloro-2-methoxybenzoic acid, sodium chloracetate, trichloraceticacid, sodium 2,2-dichloropropionate, sodium 2,2,3-trichloropropionate,N,N-dimethyl-N′-phenyl urea and its trichloracetic salt, thetrichloracetate of N,N-dimethyl-N′-(4-chlorophenyl) urea, coppersuphate, iron sulphate, 1,1′-dimethyl-4,4′-bipyridylium dichloride,1,1′-bis(3,5-dimethyl-4-morpholinyl)-carbonylmethyl-4,4′-bipyridyliumdichloride, 9,10-dihydro-8a, 10a-diazaphenanthrene dibromide,3-amino-1,2,4-triazole, symmetrical triazines and the like.

Suitable insecticides include one or more of the following: dimethylacetylphosphoramidothioate; ethanimidamide,N-{(6-chloro-3-pyridinyl)methyl}-N′-cyano-N-methyl-, (E)-(90)(CA Indexname); hydrazinecarboxylic acid, 2-(4-methoxy{1,1′-biphenyl}-3-YL)-,1-methylethyl ester (9Cl) (CA Index Name);methyl{1,1′-biphenyl}-3-YL)methyl3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethylcyclopropanecarboxylate,{1.alpha.,3.alpha.(Z)}-(.+−.)-; naphthyl-n-methylcarbamate;pyrrole-3-carbonitrile,4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl);chloro-alpha-(1-methylethyl)benzeneacetic acid,cyano(3-phenoxyphenyl)methyl esteramino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(1,R,S)-(trifluoromethyl)sulfinyl)-1H-pyrazole-3-carbonitrile;benzoic acid, 4-chloro-, 2-benzoyl-2-(1,1-dimethylethyl)hydrazide (9Cl)(CA Index Name); pyrethrins;deoxy-2,3,4-tri-o-methyl-alpha-L-mannopyranosyl)oxy)-13-{{5-(dimethylamino)tetrahydro-??methyl-2H-pyran-2-YL}oxy}-9-ethyl-2,3,3A,5A,5B,6,9,10,11,12,13,14,16A,16B-tetradecahydro-14-methyl-1H-as-indaceno{3,2-D}oxacyclododecin-7,15-dione,(cont'd qual; oxadiazin-4-imine,3-(2-chloro-5-thiazolyl)methylytetrahydro-5-methyl-N-nitro-(9Cl) and thelike.

Suitable fungicides for use in the present invention includetetrachloroisophthalonitrile;ethoxy-3-(trichloromethyl)-1,2,4-thiadiazole;dichlorophenyl)-4-propyl-1,3-dioxolan-2-YL)methyl)-1H-1,2,4-triazole;carbamic acid,2-1-(4-chlorophenyl)-1H-pyrazol-3-ylyoxyymethylyphenylymethoxy-methylester (CAS name); dimethyl((1,2-phenylene)bis(iminocarbonothioyl))bis(carbamate) and the like.

Suitable plant growth regulators for use in the present inventionincludeRS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-YL)pentan-3-OL;cyclohexanecarboxylic acid,4-(cyclopropylhydroxymethylene)-3,5-dioxo-,ethyl ester.

Other examples of biologically active ingredients which may be employedin preparing the granular compositions of this invention include(z)-11-tetradecenyl acetate; 1,2-benzisothiazolin-3-on;1,2-Dibromoethane; 1,3-dichloro-5,5-dimethylhydantoine;1,3-dichloro-5-ethyl-5-methylhydantoine;1-bromo-3-chloro-5,5-dimethylhydantoine; 1-Chloro-2,3-epoxyethane;1-methylcyclopropene;1-naftylacetamide; 1-naftylacetic acid;2-(thiocyanomethylthio)benzothiazole; 2,2 dibromo-3-nitrilopropionamide;2,T-Bipyridyl; 2,2-dithiobisbenzamide; 2,4,5-T, 2,4-D, 2,4-DB;2,4-Dichloroanisole; 2,4-Dichlorobenzoic acid; 2,4-Dichlorophenol;2,6-Dichlorophenol; 2-Aminopyridine; 2-bromo-2-nitro-1,3-propanediol;2-bromo-4-hydroxyacetofenon; 2-phenylfenol;2-methyl-4-isothiazolin-3-on; 2-methylthio-4-tert.butylamino-cyclopropylamino-s-triazine; 3-indolylacetic acid;4,4′-Bipyridyl; 4,6-Dichloro-2-methylphenoxyacetic acid;4,6-Dichloro-o-cresol; 4,6-Dichloro-o-tolyloxyacetic acid;4-chloro-2-benzylfenol; 4-chloro-3-methyl-sodiumfenolate;4-Chloro-m-cresol; 4-Chloro-o-cresol;5-chloro-2-methyl-4-isothiazolin-3-on; 5-oxo-3,4-dichloro-1,2-dithiol;6-Chloro-2-methylphenoxyacetic acid; 6-Chloro-o-tolyloxyacetic acid;6-Chloro-p-cresol; abamectine; Acephate; acetamiprid; aclonifen;Alachlor; Aldicarb; Aldrin; alkylarylpolyglycolether;alkyldimethylbenzylammoniumchloride;alkyldimethylethylbenzylammoniumchloride;alkyltrimethylammoniumchloride; alpha-Cypermethrin; alpha-Cypermethrin;aluminium-phosphide; aluminiumsulfate; Ametryn; amfotensides; Amidate;amidosulfuron; Aminocarb; Amitraz; Amitrole; ammoniumbichromate;ammoniumbifluoride; ancymidol; Anilazine; arsenepentoxide; Asulam;Atrazine; auxin; azaconazole; azadirachtine-a; azamethifos;Azinphos-methyl; azocyclotin; azoxystrobin; bariummetaborate; amber aciddialdehyde; beauveria bassiana; benazolin-ethyl; Bendiocarb;Benfluralin; Benfuracarb; Benomyl; Bensulfuron-methyl; Bensultap;Bentazone; benthiavalicarb-isopropyl; Benzoylprop-ethyl; benzyladenine;benzylbenzoate; beta-Cyfluthrin; BHTO; bifenazate; Bifenox; bifenthrin;Binapacryl; Bioallethrin; Bis(ethylenediamine) copper; Bitertanol;bitumen; borate; Borax; boric acid; boscalid; Brodifacoum; Bromacil;Bromadiolone; Bromocresol green; Bromophenol blue; Bromophos;Bromothymol blue; Bromoxynil; bromuconazole;bromo-chloro-5,5-dimethylhydantoine mixtures; bromofenoxim;bromonitrostyrene; bromopropylate; buminafos; bupirimate; buprofezin;Butachlor; butocarboxim; butoxycarboxim; Butylate; Butylmagnesiumchloride; calciumcyanide; calciumhypochlorite; Captan; carbaryl;carbeetamide; Carbendazim; carbendosulf; Carbetamide; Carbofuran; Carbondisulphide; Carbosulfan; carboxin; carfentrazone-ethyl; Cartap;Cetylpyridinium bromide; Chinomethionat; chlofentezin; Chloramben;Chlordimeform; chlordioxide; chlorfacinon; chlorfenoxyacetic acid;Chlorfenvinphos; Chloridazon; Chlormequat; Chlorobenzilate;chlorobromuron; chlorodecone; Chloropropylate; Chlorothalonil;chlorotoluron; Chloroxuron; Chlorphoxim; Chlorpropham; Chlorpyrifos;Chlorsulfuron; Chlorthal; cinidon-ethyl; cis-dichloropropene;clodinafop-propargyl; Clofentezine; clomazone; clopyralid; codlemon;Congo red; coniothyrium minitans; Copper; Copper ethylenediaminesulphate; copper(i)oxide; copper(ii)carbonatehydroxide; copper(ii)oxide;copperhydroxide; coppernaftenate; copperoxychinolate; copperoxychloride;copperresinate; coppersilicofluoride; coppersulfate; copperthiocyanate;Coumatetralyl; Cyanazine; hydrocyanic acid; cyazofamid; Cycloate;Cycloxydim; cyfenothrin; Cyfluthrin; Cyhexatin; Cymoxanil; Cypermethrin;Cyproconazole; cyprodinil; cyromazin; Dalapon; d-allethrin; daminozide;dazomet; DDT; Deltamethrin; d-empenthrin; Deschlorophosphamidon;desmedifam; Desmetryn; d-fenothrin; dialkyldimethylammoniumchloride;Diazinon; Diazomethane; Dicamba; Dichlobenil; dichlofenthion;Dichlofluanid; dichloran; Dichlorodifluoromethane; dichloropropene;Dichlorprop; Dichlorvos; Diclofop; Dicofol;didecyldimethylammoniumchloride; Dieldrin; dienochlor; diethofencarb;diethyl-m-toluamide; difenacum; difenoconazole; difethialon;Diflubenzuron; Diflufenican; Dimedone derivative; Dimercury dicyanide;dimethenamide;Dimethoate; Dimethomorph; Dimethyl sulphate; disodiumoctaborate; disodiumcyanodithioimidocarbonate; dinoseb; Dinoterb;Dioxane; Diquat; Diquat dibromide; Disulfoton; Dithianon;dithiocarbamate; Dithizone; diuron; d-karvon; dnoc;dodecyldihydroxyethylbenzylammoniumchloride; dodemorf; Dodine;d-tetramethrin; d-trans-Allethrin; Dustability; Edifenphos; Endosulfan;Endrin; enilconazol; Epichlorhydrin; Epoxiconazole; EPTC; Erichrome;Esfenvalerate; Ethephon; Ethiofencarb; Ethion; Ethirimol; Ethofumesate;ethoprofos; ethyl 3-(n-n-butyl-n-acetyl)aminopropion; ethyleneoxide;Ethylenediamine tetraacetic acid; Etofenprox; etridiazole; etrimfos;ETU; famoxadone; fenamidone; fenamifos; fenarimol; Fenbutatin oxide;fenchlorazole-ethyl; fenhexamide; Fenitrothion; fenmedifam; Fenobucarb;Fenoprop; fenothrin; fenoxaprop-p-ethyl; fenoxycarb; fenpiclonil;fenpropathrin; fenpropidin; Fenpropimorph; Fensulfothion; Fenthion;Fentin; Fentin acetate; Fentin hydroxide; Fenvalerate; ferri phosphate;Ferroin sulphate; ferrosulfate; Fipronil; flocoumafen; florasulam;Fluazifop-butyl; Fluazifop-P-butyl; fluazinam; flucycloxuron;fludioxonil; flufenacet; Fluometuron; fluorglycofen-ethyl;fluoxastrobin; flurenol; fluroxypyr; Flusilazole; flutolanil; Folpet;fonofos; foramsulfuron; Formaldehyde; Formothion; fosalon;fosetyl-aluminium; fosfamidon; fosmet; fosthiazate; foxim; fuberidazole;furalaxyl; furathiocarb; gibbereline; gibberella; Glufosinate;glufosinate-ammonium; glutaraldehyde; glycolbromoacetate;glyphosate-trimesium; Glyphosate; guazatine; haloxyfop-ethoxyethyl;haloxyfop-p-methyl; heptenofos; Hexadecanoic acid; Hexazinone;hexythiazox; fenoxacrim; hydramethylnon; Hydrogen sulphide;Hydroxylammonium chloride; hymexazole; Icaridin; Imazalil;imazamethabenz-methyl; Imidacloprid; indoxacarb;iodosulfuron-methyl-sodium; ioxynil; iprodion; isofenphos; isoproturon;isoxaflutole; iodofore; kasugamycine; kresoxim-methyl;lambda-Cyhalothrin; lenacil; lindane; linuron; magnesiumphosphide;malathion; maleine hydrazide; mancozeb; maneb; MCPA; m-Cresol; mecoprop;mecoprop-p; mepanipyrim; mesotrione; metalaxyl; metalaxyl-m;metaldehyde; metamitron; metam-sodium; metarhizium anisopliae;metazachlor; methabenzthiazuron; methamidophos; methidathion;methiocarb; methomyl; methoprene; methoxyfenozide; methylbromide;methylenebisthiocyanate; methylnaftylaceetamide; methylnaftylaceticacid; metiram; metobromuron; metolachlor; metoxuron; metribuzin;metsulfuron-methyl; mevinphos; milbemectin; molinate; monobromoaceticacid; monocarbamide-dihydrogensulfate; monolinuron; monuron;myclobutanil; N-(2-ethylhexyl)-8,9,10-tribomene-2,3-dicarboxamide;n,n-diallyldichloroaceetamide; sodium bichromate; sodium bisulfite;sodium bromide; sodium chlorite; sodium dichloroisocyanurate; sodiumfluoracetate; sodium hydroxide; sodium hypochlorite; sodium octaborate;sodium perborate; sodium-p-toluenesulfonchloramide; nicosulfuron;nitrothal-isopropyl; n-octylbicycloheptenedicarboximide; nonylfenolethoxylate; nuarimol; O,O-Dimethyl methylphosphoroamidothioate;O,O-Dimethyl phosphoroamidothioate; O,O-DimethylS-methylcarbamoylmethylphosphorodithioate; O,S-Dimethylmethylphosphoroamidothioate; O,S-Dimethyl4-nitrophenylphosphorothioate;o-Cresol; octanoic acid; octylfenoxypolyethoxyethanol ;octylisothiazolin-3-on; omethoate; oxadixyl; oxamyl; oxy-demeton-methyl;paclobutrazol; paecilomyces fumosoroseus; paraformaldehyde; paraquat;paraquat-dichloride; parathion (ethyl); parathion-methyl;p-chloro-m-cresol; p-Cresol; penconazole; pencycuron; pendimethalin;permethrin; phenoxyalkanoic herbicides; p-hydroxyphenylsalicylamide;picloram; picoxystrobin; piperonylbutoxide; pirimicarb;pirimiphos-ethyl; pirimiphos-methyl;poly[oxyethylene(dimethyliminio)ethylene; polybutenen; Potassiumbichromate; Potassium bifluoride; Potassium hydroxide;Potassium-n-methyldithiocarbamate; prochloraz; procymidon; profam;prohexadione-calcium; prometryn; propachlor; propamocarb-hydrochloride;propaquizafop; propetamphos; propham; propiconazole; propoxur;propyzamide; prosulfocarb; prothioconazole; pymetrozine; pyraclostrobin;pyrazophos; pyrethrinen; pyridaben; pyridate; pyrifenox; pyrimethanil;pyriproxyfen; quinmerac; quinoclamin; quinoxyfen; quizalofop-ethyl;quizalofop-p-ethyl; rape seed oil; rimsulfuron; salicylic acid;sethoxydim; simazine; s-methoprene; s-metolachlor; spinosad;spirodiclofen; spiromesifen; streptomyces griseoviridis;streptomycine-sulfate; sulcofuron; sulcotrione; sulfotep; Sulphur;tebuconazole; tebufenpyrad; teflubenzuron; tefluthrin; temephos;tepraloxydim; terbufos; terbuthylazine; terbutryn;tetra-acetylethylenediamine; tetrachlorvinfos; tetradifon; tetramethrin;thiabendazol; thiacloprid; thiamethoxam; thifensulfuron; Thiobencarb;thiocyclam hydrogeneoxalate; thiodicarb; thiofanate-methyl; thiometon;thiram; thiuram disulphide; tolclofos-methyl; tolylfluanid;transfluthrin; triadimefon; triadimenol; tri-allate; triazamate;triazophos; tributyltinacrylatecopolymer; tributyltinfluoride;tributyltinphosphate; tributyltinmethacrylate; tributyltinoxide;trichlorfon; trichlorisocyanuric acid; trichoderma harzianum rifai t-22;triclopyr; tridemorf; triphenyltinfluoride; trifloxystrobin;triflumizol; triflumuron; trifluralin; triflusulfuron-methyl; triforine;trinexapac-ethyl; urea herbicides; validamycine; vamidothion;verticillium dahliae kleb.; verticillium lecanii; saturated fatty acids;vinclozolin; warfarin; hydrogenperoxide; Silverthiosulfate; zineb;zincborate; zincnaftenate; zincoxalate; zincoxide; zincpyrithione;zincsilicofluoride; ziram; γ-Chlorophosphamidon and the like.

To ensure that the granular agrochemical composition releasesessentially all of its active ingredient (ie, greater than 90% and,preferably, greater than 99%), the core material should release slowerthan the active ingredient. Otherwise, residues of active ingredientwould remain in the controlled release system after complete release ofthe core material.

In a preferred embodiment of the present invention, the granular corematerial employed for preparing the compositions is at least partiallywater soluble and may comprise any of a variety of well known, standardNPK or other such fertilizer granules such as those described inEuropean Community Regulation (EC) No. 2003/2003. Alternatively, thecore material may be a water-soluble salt or other such material, e.g.sodium-salts or calcium-salts.

Also, other non-ionic materials may be suitable for use in forming thecore of the present compositions, particularly, those which can provideosmotic pressure when dissolved. Examples, of such materials are sugarand urea granules.

Typically, the materials for use in forming the core for thecompositions of this invention should have a solubility of about 2 toabout 800 g/l, preferably, about 120-450 g/l. Also, the core materialshould be shaped as a granule having a diameter of about 0.35 to about 6mm, preferably, about 0.72-4 mm for better distribution of the product.

Preferably, the wax material to be employed for use in preparing thefirst coating layer should have a melting point between about 50° C. andthe degradation temperature of the active ingredient or core material,preferably above about 80° C. The wax can be hydrophobic orhydrophillic.

Exemplary of suitable waxes for use herein are higher alkenes;stearamides; polyolefines such as polyethylene, oxidized polyethylenes,polypropylene, polyisobutylene, styrene-based polymers; (block)copolymers of polyolefines; polyesters; (block) copolymers ofpolyesters; polyethers, e.g. poly(ethylene oxide), poly(propyleneoxide); (block) copolymers of polyethers; vinyl resins such aspoly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride),poly(vinylidene chloride), poly(vinyl pyrrolidone), poly(vinyl acetal),poly(vinyl methylacetamide); acrylic polymers; cellulose derivatives,e.g. celluloseacetate; polyamides; polyamines; polyimides;polycarbonates; polysulfones; polysulfides; polysaccharides. Also blendsof these waxes can be used.

In a further preferred embodiment of this invention the biologicallyactive ingredient or plant protection product for incorporation in thewax to form the first coating layer should be selected from the groupconsisting of insecticides, herbicides, fertilizers, growth regulators,pheromones, biostimulants, acaricides, miticides, nematocides,fungicides and mixtures thereof and the like.

The controlled release systems of this invention enable economicalapplication of a total amount of active ingredient necessary for seasonlong control without increased risk of leaching, phytotoxicity for cropsand is safe for users. The active ingredient is applied without the useof a solvent. Thus, low-solubility active ingredients can be used.Significantly, the system is efficient. At most, only very limitedamounts, preferably less than about 10% by weight and, most preferably,less than about 1% by weight, of the active ingredient should be leftinside the system.

In order to achieve the high efficiency of release characteristics ofthe compositions of the present invention, it is preferred to adjust thewater-solubility of the core material to correspond to thewater-solubility of the active ingredient. When the corematerial-solubility is too high compared to the activeingredient-solubility, all of the core-material may be released beforethe release of all the active ingredient. This results in residue ofactive ingredient in the granules which is not desirable from anenvironmental and commercial point of view. If the solubility of thecore material is too low compared to the solubility of the activeingredient, too much of the core material may be left in the compositionafter the release of the active. This results in an inefficient use ofthe core material.

The solubility of the active ingredient and core material may beinfluenced by additives, such as ionic or non-ionic surfactants,water-soluble polymers or complexing agents. Not all active ingredientsdemonstrate good water-solubility. Increasing the solubility of anactive ingredient, for example, by using a non-ionic surfactant for theactive ingredient application renders the actives more soluble and maymake the compositions of this invention more widely applicable. Not onlythe solubility of the core material but, also, the dissolving rate ofthe core material versus the active ingredient should be considered informulating the compositions of this invention. Typically, the ratio ofcore material to active ingredient should be about 1000 to about 0.1and, preferably, about 200-10. After the release period, less than about10%, preferably, less than 1% of the initial amount of active ingredientshould be present inside the controlled release system. To achieve thedesired release longevity of the compositions of this invention, thecoating thickness employed should be matched with the solubility of thecore material and the active ingredient.

Furthermore, it should be noted that the longevity of release of theactive ingredients of the present compositions can be modified byvarying the amount of polymeric coating employed. Alternatively, thewater-permeability of the polymer coating can be changed. The polymercoating layer can be formed from any (semi-)water-permeable polymericmaterial, including copolymers, known in the art such as knownthermosetting resins, thermoplastic resins and other polymeric materialsor latex polymers and mixtures thereof The polymer coating enables slowrelease of the active ingredient over a period of about 6 to about 104weeks, preferably, about 3-6 months.

Exemplary of suitable polymers for use in the present invention are suchthermoplastic coating materials as vinyl resins such as poly(vinylacetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidenechloride), poly(vinyl pyrrolidone), poly(vinyl acetal), poly(vinylmethylacetamide); polyolefines such as polyethylene, polypropylene,polyisobutylene; styrene-based polymers; acrylic polymers; polyesterssuch as poly(alkylene terephthalate), poly(caprolactone); poly(oxyalkylene)s, such as poly(ethylene oxide), poly(propylene oxide);cellulose derivatives, such as celluloseacetate; polyamides; polyamines;polycarbonates; polyimides; polysulfones; polysulfides; polysaccharidesand the like.

Suitable thermosetting polymeric coating materials for use hereininclude polyesters such as alkyds or modified alkyds; epoxy resins;urethane resins; and aminoplastics.

In a most preferred embodiment of this invention, the polymericcomposition for use in forming the second coating layer comprises adicyclopentadiene (“DCPD”) polymeric product (containing either linseedoil or an alkyd resin based on a soybean oil) such the polymer coatingsemployed to produce such fertilizers as those sold by the Scotts Companyunder the trademark Osmocote® as disclosed in U.S. Pat. No. 3,223,518and U.S. Pat. No. 4,657,576.

In preparing the present compositions, the active ingredient is appliedonto the granular core material with a wax. Preferably the activeingredient/wax combination is a solid at room temperature and it isapplied onto the granular core material as a liquid. The activeingredient can be mixed with a (molten) wax and applied drop wise orsprayed onto the granular material. The active ingredient does not needto dissolve. The mixture of active ingredient and wax can be applied asa dispersion. In addition, functional additives such as surfactants,which are used to modify the water solubility, can be applied with theactive ingredients. The use of ionic or non-ionic surfactants enablesuse of active ingredients in the present compositions that have a lowsolubility in water, thus, broadening their applicability. Also, waxesthat are non-ionic surfactants can be used herein.

The present invention encompasses both granular controlled releaseagrochemical compositions and processes for the preparation thereof andaddresses the problems encountered with regard to functionality of priorcompositions in terms of active ingredient release over an extendedperiod of time.

The compositions and processes of the present invention are furtherillustrated by the examples below. The examples serve only to illustratethe invention and should not be interpreted as limiting since furthermodifications of the disclosed invention will be apparent to thoseskilled in the art. All such modifications are deemed to be within thescope of the invention as defined in the claims.

EXAMPLE 1

A sample of the granular agrochemical compositions of the presentinvention was prepared employing an 0-2-40 fertilizer granule obtainedfrom The Scotts Company (Howden, UK) as the granular core material. Thisgranular core was predominantly composed of potassium sulfate . Thesample composition was prepared by initially heating 50 g of the 0-2-40fertilizer granules (1.7-2.0 mm) in a rotating drum to 110° C. Then,0.75 g of a non-ionic surfactant wax (apolyethyleneglycol-block-polyethylene, cas nr.: [251553-55-6], hydroxylnumber 52.00 mg KOH/g, containing 20% (by weight) polyethylene glycol,obtained from Sigma-Aldrich), was melted and 0.25 g of a biologicallyactive ingredient (imidacloprid, obtained from Sigma-Aldrich) was mixedinto in the molten wax.

Then, the resulting mixture of imidacloprid and wax was added to thewarm fertilizer (potassium sulfate) granules to form a coating layer onthe granular core. The granules with the imidacloprid and wax coatingthereon were allowed to cool to room temperature. Subsequently, a secondcoating layer was applied over the imidacloprid and wax coating layeraccording to the following procedure. The active-impregnated granuleswere heated 15 minutes in a rotating flask in an oil-bath at 95° C. Amodified unsaturated oil copolymer based alkyd resin sold under thetrade name Necolin S9363 by Ashland-Sudchemie-Kernfest GmbH, Germany,was added to the warm granules over a 40 minute period. The solidcontent of the added resin was 40%. White spirit was used as a solventand a drier was used to enhance the curing. During the process ofapplying the second polymer coating layer, air was purged through thesystem to evaporate the solvent from the resin. After coating 5.5 pph(parts per hundred by weight) on the granular composition having thefirst coating layer thereon, the resulting composition was cooled toroom temperature and was ready for testing. The imidaclopridconcentration in this composition was 0.30% by weight as determined bystandard High Performance Liquid Chromatography chemical analyticalanalysis techniques.

The test sample of this Example 1 was subjected to release testingwherein the release of the active ingredient from the coated granularcomposition was evaluated in water in a so-called waterleach test. Forthis waterleach test, 200 ml of water was added to 10 g of the coatedgranular composition. Then the sample was stored at 21° C. and the waterwas replaced completely with fresh water after 1 day and at weeklyintervals thereafter. The removed water was analyzed on activeingredient content with standard analytical methods. For example, theimidacloprid active ingredient release from the test samples of Example1 was analyzed with HPLC, column: inertsil ODS-2 150×4.6 mm, eluensacetonitrile/water (pH=3 with phosphoric acid).

The release profile was calculated from the initial active ingredientconcentration in the granule. The core dissolution was calculated fromthe measured conductivity. The measured conductivity can be translatedinto a total amount of nutrients released using the appropriatecalibration constants. These calibration constants are specific for aparticular type of fertilizer and are determined experimentally.

The result of this analytical evaluation was graphed on the basis ofpercentage release of active ingredient versus percentage release ofwater soluble core material over a time period up to 287 days asillustrated in FIG. 1. As can be seen from the graphic display in FIG.1, the granular composition having the biologically active imidaclopridingredient incorporated into the non-ionic surfactant wax provided aneffective and efficient system for release of the active ingredient overa period of greater than 30 days. In fact, as demonstrated by theresults shown in FIG. 1, the compositions of this invention provided arelease of about 95% (by weight) of the active ingredient over a periodof 287 days from the date of initial exposure to moisture while aboutonly about 50% (by weight) of the core material was released over thatsame time period so that about 50% (by weight) of the water solubleportion of the granular core material remained within the granularcomposition over the 287 day duration.

EXAMPLE 2

The composition produced in accordance with this Example 2 isdistinguishable from the compositions produced in accordance withExample 1 in regard to the wax material employed in forming the firstcoating layer of test sample of the granular agrochemical composition ofthe present invention. The procedure used to produce the test sample ofthis Example 2 was in accordance with the process of Example 1.

Specifically, an 0-2-40 fertilizer granule obtained from The ScottsCompany which was predominantly composed of potassium sulfate wasemployed as the granular core material for the sample composition whichwas prepared by initially heating 50 g of the 0-2-40 fertilizer granules(1.7-2.0 mm) in a rotating drum to 110° C. Then, 0.75 g of apolyethyleneglycol-block-polyethylene, cas nr.: [97953-22-5], hydroxylnumber 55.00 mg KOH/g, containing 50% (by weight) polyethylene glycol,obtained from Sigma-Aldrich) was melted and 0.25 g of a biologicallyactive ingredient (imidacloprid, obtained from Sigma-Aldrich) was mixedinto the molten wax. This wax differed from the wax employed in Example1 but possessed similarly suitable surfactant characteristics for theimidacloprid biologically active ingredient which was incorporated bymixing into in the molten wax as described in Example 1.

Then, the resulting mixture of imidacloprid and wax was added to thewarm fertilizer (potassium sulfate) granules to form a coating layer onthe granular core. The granules with the imidacloprid and wax coatingthereon were allowed to cool to room temperature. Subsequently, the samepolymeric second coating layer as described in Example 1 was appliedover the imidacloprid and wax coating layer employing the same procedureas in Example 1 to produce the granular composition for testing. Theimidacloprid concentration in the composition of this Example 2 was0.22% (by weight) as determined by standard High Performance LiquidChromatography chemical analytical analysis techniques.

The composition of this Example 2 was subjected to the release testingprocedure as described in Example 1 and the results of this testing isillustrated in FIG. 2. As can be seen from the graphic display in FIG.2, this granular composition having the biologically active imidaclopridingredient incorporated into the wax provided an effective and efficientsystem for release of the active ingredient over a period of greaterthan 30 days. In fact, as demonstrated by the results shown in FIG. 2,the composition of this invention provided a release of about 96% (byweight) of the active ingredient over a period of 287 days from the dateof initial exposure to moisture while only about 65% (by weight) of thecore material was released over that same time period so that about 35%(by weight) of the water soluble portion of the granular core materialremained within the granular composition over the 287 day duration.

EXAMPLE 3

The composition produced in accordance with this Example 3 isdistinguishable from the compositions produced in accordance withExample 2 in regard to the amount of the active ingredient which wasincorporated into the wax material in forming the first coating layer oftest sample of the granular agrochemical composition of the presentinvention.

The procedure used to produce the test sample of this Example 3 was inaccordance with the process of Example 1. Specifically, an 0-2-40fertilizer granule obtained from The Scotts Company which waspredominantly composed of potassium sulfate was employed as the granularcore material for the sample composition which was prepared by initiallyheating 50 g of the 0-2-40 fertilizer granules (1.7-2.0 mm) in arotating drum to 110° C. Then, 0.75 g of apolyethyleneglycol-block-polyethylene, cas nr.: [97953-22-5], hydroxylnumber 55.00 mg KOH/g, containing 50% polyethyleneglycol, obtained fromSigma-Aldrich) was melted and 0.75 g of a biologically active ingredient(imidacloprid, obtained from Sigma-Aldrich) was mixed into the moltenwax. This amount of biologically active ingredient is higher than theamount used in Example 2.

Then, the resulting mixture of imidacloprid and wax was added to thewarm fertilizer (potassium sulfate) granules to form a coating layer onthe granular core. The granules with the imidacloprid and wax coatingthereon were allowed to cool to room temperature. Subsequently, the samepolymeric second coating layer as described in Example 1 was appliedover the imidacloprid and wax coating layer employing the same procedureas in Example 1 to produce the granular composition for testing. Theimidacloprid concentration in the composition of this Example 3 was0.95% by weight as determined by standard High Performance LiquidChromatography chemical analytical analysis techniques.

The composition of this Example 3 was subjected to the release testingprocedure as described in Example 1 and the results of this testing isillustrated in FIG. 3. As can be seen from the graphic display in FIG.3, this granular composition having the biologically active imidaclopridingredient incorporated into the wax provided an effective and efficientsystem for release of the active ingredient over a period of greaterthan 30 days. In fact, as demonstrated by the results shown in FIG. 3,the composition of this invention provided a release of about 86% (byweight) of the active ingredient over a period of 175 days from the dateof initial exposure to moisture while only about 67% (by weight) of thecore material was released over that same time period so that about 33%(by weight) of the water soluble portion of the granular core materialremained within the granular composition over the 175 day duration.

EXAMPLE 4

The composition produced in accordance with this Example 4 isdistinguishable from the compositions produced in accordance withExample 1 in regard to the active ingredient which was incorporated intothe wax material in forming the first coating layer of test sample ofthe granular agrochemical composition of the present invention and inregard to polymer composition which was employed in forming the secondcoating layer on the compositions. The procedure used to produce thetest sample of this Example 4 was in accordance with the process ofExample 1.

Specifically, an 0-2-40 fertilizer granule obtained from The ScottsCompany which was predominantly composed of potassium sulfate wasemployed as the granular core material for the sample composition whichwas prepared by initially heating 50 g of the 0-2-40 fertilizer granules(1.7-2.0 mm) in a rotating drum to 110° C. Then, 3.5 g of the non-ionicsurfactant wax of Example 1 (a polyethyleneglycol-block-polyethylene,cas nr.: [251553-55-6], hydroxyl number 52.00 mg KOH/g, containing 20%by weight polyethyleneglycol, obtained from Sigma-Aldrich), was meltedand 3.5 g of a Fosetyl-Aluminum biologically active ingredient obtainedfrom Bayer CropSciences was incorporated by mixing into the molten waxby the same procedure described in Example 1.

Then, the resulting mixture of Fosetyl-Aluminum and wax was added to thewarm fertilizer (potassium sulfate) granules to form a coating layer onthe granular core. The granules with the Fosetyl-Aluminum and waxcoating thereon were allowed to cool to room temperature. Subsequently,a polymeric second coating layer was applied over the Fosetyl-Aluminumand wax by the process described in Example 1 to produce the granularcomposition for testing. The polymer employed as the second coatinglayer was a modified unsaturated oil copolymer based alkyd resin soldunder the trade name Necolin 4071 by Ashland-Sudchemie-Kernfest GmbH,Germany. The Fosetyl-Aluminum concentration in the composition of thisExample 4 was 4.75% (by weight) as determined by standard HighPerformance Liquid Chromatography chemical analytical analysistechniques.

The composition of this Example 4 was subjected to the release testingprocedure as described in Example 1 except that the Fosetyl-Aluminiumrelease was analyzed with ion-chromatography column: Phenomenex starionA300: 1050×4.6 mm, eluens 5% acetone in water, with 1 mM HNO₃ and 3 mMNaNO₃ and the results of this testing is illustrated in FIG. 4. As canbe seen from the graphic display in FIG. 4, this granular compositionhaving the biologically active Fosetyl-Aluminum ingredient incorporatedinto the wax provided an effective and efficient system for release ofthe active ingredient over a period of greater than 30 days. In fact, asdemonstrated by the results shown in FIG. 4, the composition of thisinvention provided release of 99% (by weight) of the active ingredientover a period of about 267 days from the date of initial exposure tomoisture while only about 50% (by weight) of the core material wasreleased over that same time period.

EXAMPLE 5

Another granular test sample compositions in accordance with thisinvention was produced utilizing a hydrophobic wax material in formingthe first coating layer. The procedure used to produce the test sampleof this Example 5 was in accordance with the process of Example 1.

Specifically, an 0-2-40 fertilizer granule obtained from The ScottsCompany which was predominantly composed of potassium sulfate wasemployed as the granular core material for the sample composition whichwas prepared by initially heating 50 g of the 0-2-40 fertilizer granules(1.7-2.0 mm) in a rotating drum to 110° C. Then, 2.5 g of a hydrophobicwax (Novoflow 02102 obtained from Holland Novochem BV, Nieuwegein, theNetherlands)—was melted and 2.5 g of a Fosetyl-Aluminum biologicallyactive ingredient obtained from Bayer CropSciences was incorporated bymixing into the molten wax by the same procedure described in Example 1.

Then, the resulting mixture of Fosetyl-Aluminum and wax was added to thewarm fertilizer (potassium sulfate) granules to form a coating layer onthe granular core. The granules with the Fosetyl-Aluminum and waxcoating thereon were allowed to cool to room temperature. Subsequently,a polymeric second coating layer was applied over the Fosetyl-Aluminumand wax by the process described in Example 1 to produce the granularcomposition for testing. The polymer employed as the second coatinglayer was a modified unsaturated oil copolymer based alkyd resin soldunder the trade name Necolin 4071 by Ashland-Sudchemie-Kernfest GmbH,Germany. The Fosetyl-Aluminum concentration in the composition of thisExample 5 was 3.5% by weight as determined by standard High PerformanceLiquid Chromatography chemical analytical analysis techniques.

The composition of this Example 5 was subjected to the release testingprocedure as described in Example 1 as modified in Example 4 and theresults of this testing is illustrated in FIG. 5. As can be seen fromthe graphic display in FIG. 5, this granular composition having thebiologically active Fosetyl-Aluminum ingredient incorporated into thehydrophobic wax provided an effective and efficient system for releaseof the active ingredient over a period of greater than 30 days. In fact,as demonstrated by the results shown in FIG. 5, the composition of thisinvention provided release of about 80% (by weight) of the activeingredient over a period of about 266 days from the date of initialexposure to moisture while only about 36% (by weight) of the corematerial was released over that same time period so that about 64% (byweight) of the water soluble portion of the granular core materialremained within the granular composition over the approximately 266 dayduration. This result demonstrates the benefits derived from employing ahydrophobic wax resulting in a slower releasing product which isdesirable when a highly soluble active ingredient is incorporatedtherein.

Although the invention has been described in its preferred forms with acertain degree of particularity, it is to be understood that the presentdisclosure has been made by way of example only. Those skilled in theart will recognize, or be able to ascertain using no more than routineexperimentation, many equivalents to the specific embodiments of theinvention described herein. Such equivalents are intended to beencompassed within the scope of the following claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated by reference into thespecification to the same extent as if each individual publication,patent or patent application was specifically and individually indicatedto be incorporated herein by reference.

1. A granular agrochemical composition comprising: a) a granular corematerial including a water soluble portion; b) a first coating layercomprising a wax composition having a biologically active ingredientincorporated therein applied on the surface of the core material; and c)a second coating layer comprising a polymeric composition applied on thesurface of the first coating layer; d) said granular compositionexhibiting a controlled rate of release of the biologically activeingredient therefrom over a period greater than about 30 days from thedate of initial exposure of the granular composition to moisture wherebyessentially all of the biologically active ingredient incorporated inthe wax material of the first coating layer is released from thegranular composition before the water soluble portion of the granularcore material is released from the granular composition.
 2. The granularagrochemical composition of claim 1 wherein the water soluble portion ofthe core material generates sufficient osmotic pressure within thegranular composition to cause the biologically active ingredient in thefirst coating layer to be released therefrom when the composition iscontacted with moisture.
 3. The granular agrochemical composition ofclaim 2 wherein the second coating layer is structured to withstand theosmotic pressure generated by the core material.
 4. The granularagrochemical composition of claim 1 wherein the water soluble corematerial is a fertilizer.
 5. The granular agrochemical composition ofclaim 4 wherein the fertilizer is selected from the group consisting ofammonium sulfate, potassium nitrate, potassium sulfate, urea, ammoniumnitrate, monopotassium sulfate, ammonium phosphate, super-phosphate,calcium phosphates, potassium phosphate, potassium chloride, magnesiumoxide, magnesium sulfate, dolomite and mixture thereof.
 6. The granularagrochemical composition of claim 4 wherein the core material includesat least one secondary nutrient or micronutrient.
 7. The granularagrochemical composition of claim 6 wherein the secondary nutrient isselected from the group consisting of calcium, magnesium, sulfur andmixtures thereof.
 8. The granular agrochemical composition of claim 6wherein the micronutrient is selected from the group consisting ofchelated or non-chelated iron, copper, zinc, manganese, boron, cobalt,chlorine, sodium, molybdenum and mixtures thereof.
 9. The granularagrochemical composition of claim 1 wherein the core material includes anon-active material.
 10. The granular agrochemical composition of claim1 wherein the core material has a solubility of about 2 to about 800g/l.
 11. The granular agrochemical composition of claim 1 wherein thecore material is shaped as a granule having a diameter of about 0.35 toabout 6 mm.
 12. The granular agrochemical composition of claim 1 whereinthe biologically active ingredient is selected from the group consistingof pesticides, insecticides, herbicides, fungicides, fertilizers, growthregulators, pheromones, biostimulants, acaricides, miticides,nematocides and mixtures thereof.
 13. The granular agrochemicalcomposition of claim 1 wherein the wax composition has a melting pointof greater than 50° C.
 14. The granular agrochemical composition ofclaim 13 wherein the wax composition is hydrophobic.
 15. The granularagrochemical composition of claim 13 wherein the wax composition ishydrophilic.
 16. The granular agrochemical composition of claim 1wherein the wax composition is water soluble.
 17. The granularagrochemical composition of claim 1 wherein the polymeric composition isa (semi-)water permeable material selected from the group consisting ofthermosetting resins, thermoplastic resins, latex polymers and mixturesthereof.
 18. The granular agrochemical composition of claim 1 whereingreater than about 90% of the biologically active ingredientincorporated in the wax composition of the first layer is released fromthe granular composition while a residual amount of the water solubleportion of the core material remains in the granular composition.
 19. Aprocess for preparing a granular agrochemical composition exhibiting acontrolled rate of release of a biologically active ingredientincorporated in the granular composition over a period greater thanabout 30 days from the date of initial exposure of the granularcomposition to moisture whereby essentially all of the biologicallyactive ingredient is released from the granular composition while atleast a residual amount of a core material remains in the granularcomposition comprising: a) providing a granular core material; b)applying a first coating layer comprising a wax composition having abiologically active ingredient incorporated therein on the surface ofthe core material; and c) applying a second coating layer comprising apolymeric composition on the surface of the first coating layer.
 20. Theprocess of claim 19 wherein the core material is at least partiallywater soluble whereby a sufficient osmotic pressure is generated withinthe granular composition to cause the biologically active ingredient inthe first coating to be released therefrom when the core material iscontacted with water.
 21. The process of claim 20 wherein the secondcoating layer is structured to withstand the osmotic pressure generatedby the core material.
 22. The process of claim 20 wherein the watersoluble core material is a fertilizer.
 23. The process of claim 22wherein the fertilizer is selected from the group consisting of ammoniumsulfate, potassium nitrate, potassium sulfate, urea, ammonium nitrate,monopotassium sulfate, ammonium phosphate, super-phosphate, calciumphosphates, potassium phosphate, potassium chloride, magnesium oxide,magnesium sulfate, dolomite and mixture thereof.
 24. The process ofclaim 22 wherein the core material includes at least one secondarynutrient or micronutrient.
 25. The process of claim 24 wherein thesecondary nutrient is selected from the group consisting of calcium,magnesium, sulfur and mixtures thereof.
 26. The process of claim 25wherein the micronutrient is selected from the group consisting ofchelated or non-chelated iron, copper, zinc, manganese, boron, cobalt,chlorine, sodium, molybdenum and mixtures thereof.
 27. The process ofclaim 19 wherein the core material includes a non-active material. 28.The process of claim 19 wherein the core material has a solubility ofabout 2 to about 800 g/l.
 29. The process of claim 19 wherein the corematerial is shaped as a granule having a diameter of about 0.35 to about6 mm.
 30. The process of claim 19 wherein the biologically activeingredient is selected from the group consisting of pesticides,insecticides, herbicides, fungicides, fertilizers, growth regulators,pheromones, biostimulants, acaricides, miticides, nematocides andmixtures thereof.
 31. The process of claim 19 wherein the waxcomposition has a melting point of greater than 50° C.
 32. The processof claim 31 wherein the wax composition is hydrophobic.
 33. The processof claim 31 wherein the wax composition is hydrophilic.
 34. The processof claim 19 wherein the wax composition is water soluble.
 35. Theprocess of claim 19 wherein the polymeric composition is a (semi-)waterpermeable material selected from the group consisting of thermosettingresins, thermoplastic resins, latex polymers and mixtures thereof. 36.The process of claim 19 wherein greater than about 90% of thebiologically active ingredient incorporated in the wax composition ofthe first layer is released from the granular composition while aresidual amount of the core material remains in the granularcomposition.
 37. An agrochemical composition which exhibits controlledrelease of a biologically active ingredient over a period greater thanabout 30 days from the date of initial exposure of the composition tomoisture at a release rate such that essentially all of the biologicallyactive ingredient is released from the composition while at least aresidual amount of a water soluble portion of a core material remains inthe granular composition, the composition comprising a granular corematerial having a first coating layer comprising a wax material having aplant protection product incorporated therein applied on the corematerial and a second polymeric coating layer applied over the firstcoating layer.
 38. The granular agrochemical composition of claim 37wherein the core material is at least partially water soluble whereby asufficient osmotic pressure is generated within the granular compositionto cause the biologically active ingredient in the first coating to bereleased therefrom when the agrochemical composition is contacted withwater.
 39. The granular agrochemical composition of claim 37 wherein thesecond coating layer is structured to withstand the osmotic pressuregenerated by the core material.
 40. The granular agrochemicalcomposition of claim 37 wherein the water soluble portion of the corematerial is a fertilizer.
 41. The granular agrochemical composition ofclaim 37 wherein the biologically active ingredient is selected from thegroup consisting of pesticides, insecticides, herbicides, fungicides,fertilizers, growth regulators, pheromones, biostimulants, acaricides,miticides, nematocides and mixtures thereof.
 42. The granularagrochemical composition of claim 37 wherein the wax composition has amelting point of greater than 50° C.
 43. The granular agrochemicalcomposition of claim 42 wherein the wax composition is hydrophobic. 44.The granular agrochemical composition of claim 42 wherein the waxcomposition is hydrophilic.
 45. The granular agrochemical composition ofclaim 37 wherein the polymeric composition is a (semi-)water permeablematerial selected from the group consisting of thermosetting resins,thermoplastic resins, latex polymers and mixtures thereof.
 46. Thegranular agrochemical composition of claim 37 wherein greater than about90% of the biologically active ingredient incorporated in the waxcomposition of the first layer is released from the granular compositionwhile a residual amount of the core material remains in the granularcomposition.